January 25, 2007 Certificate Evidencing Fixed/Floating Rate CommonSecurities of First California Capital Trust I

Exhibit 4.2

THIS COMMON SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE OFFERED, SOLD, PLEDGED OR OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EXEMPTION FROM REGISTRATION.

THIS CERTIFICATE IS NOT TRANSFERABLE EXCEPT IN COMPLIANCE WITH SECTION 8.1 OF THE DECLARATION.

January 25, 2007

Certificate Evidencing Fixed/Floating Rate Common Securities

of

First California Capital Trust I

First California Capital Trust I, a statutory trust created under the laws of the State of Delaware (the “Trust”), hereby certifies that National Mercantile Bancorp (the “Holder”) is the registered owner of common securities of the Trust representing undivided beneficial interests in the assets of the Trust (the “Common Securities”). The Common Securities represented hereby are issued pursuant to, and the designation, rights, privileges, restrictions, preferences and other terms and provisions of the Common Securities shall in all respects be subject to, the provisions of the Amended and Restated Declaration of Trust of the Trust dated as of January 25, 2007, among Scott A. Montgomery and David R. Brown, as Administrators, Wilmington Trust Company, as Delaware Trustee, Wilmington Trust Company, as Institutional Trustee, National Mercantile Bancorp, as Sponsor, and the holders from time to time of undivided beneficial interest in the assets of the Trust including the designation of the terms of the Common Securities as set forth in Annex I to such amended and restated declaration, as the same may be amended from time to time (the “Declaration”). Capitalized terms used herein but not defined shall have the meaning given them in the Declaration. The Holder is entitled to the benefits of the Guarantee to the extent provided therein.  The Sponsor will provide a copy of the Declaration, the Guarantee and the Indenture to the Holder without charge upon written request to the Sponsor at its principal place of business.

As set forth in the Declaration, when an Event of Default has occurred and is continuing, the rights of Holders of Common Securities to payment in respect of Distributions and payments upon Liquidation, redemption or otherwise are subordinated to the rights of payment of Holders of the Capital Securities.

Upon receipt of this Certificate, the Holder is bound by the Declaration and is entitled to the benefits thereunder.

By acceptance of this Certificate, the Holder agrees to treat, for United States federal income tax purposes, the Debentures as indebtedness and the Common Securities as evidence of undivided beneficial ownership in the Debentures.

This Common Security is governed by, and construed in accordance with, the laws of the State of Delaware, without regard to principles of conflict of laws.

Signature appears on the following page

IN WITNESS WHEREOF, the Trust has duly executed this certificate.

REVERSE OF COMMON SECURITY

Distributions payable on each Common Security will be payable at an annual rate equal to [RATE]% beginning on (and including) the date of original issuance and ending on (but excluding) the Distribution Payment Date in March 2012 and at an annual rate for each successive period beginning on (and including) the Distribution Payment Date in March 2012, and each succeeding Distribution Payment Date, and ending on (but excluding) the next succeeding Distribution Payment Date (each a “Distribution Period”), equal to 3-Month LIBOR, determined as described below, plus 1.60% (the “Coupon Rate”), applied to the stated liquidation amount of $1,000.00 per Common Security, such rate being the rate of interest payable on the Debentures to be held by the Institutional Trustee. Distributions in arrears will bear interest thereon compounded quarterly at the Distribution Rate (to the extent permitted by applicable law).  The term “Distributions” as used herein includes cash distributions and any such compounded distributions unless otherwise noted.  A Distribution is payable only to the extent that payments are made in respect of the Debentures held by the Institutional Trustee and to the extent the Institutional Trustee has funds available therefor.  As used herein, “Determination Date” means the date that is two London Banking Days (i.e., a business day in which dealings in deposits in U.S. dollars are transacted in the London interbank market) preceding the commencement of the relevant Distribution Period.  The amount of the Distribution payable (i) for any Distribution Period commencing on or after the date of original issuance but before the Distribution Payment Date in March 2012 will be computed on the basis of a 360-day year of twelve 30-day months, and (ii) for the Distribution Period commencing on the Distribution Payment Date in March 2012 and each succeeding Distribution Period will be calculated by applying the Distribution Rate to the stated liquidation amount outstanding at the commencement of the Distribution Period on the basis of the actual number of days in the Distribution Period concerned divided by 360.

“3-Month LIBOR” as used herein, means the London interbank offered interest rate for three-month U.S. dollar deposits determined by the Debenture Trustee in the following order of priority:  (i) the rate (expressed as a percentage per annum) for U.S. dollar deposits having a three-month maturity that appears on Telerate Page 3750 as of 11:00 a.m. (London time) on the related Determination Date (“Telerate Page 3750” means the display designated as “Page 3750” on the Moneyline Telerate Service or such other page as may replace Page 3750 on that service or such other service or services as may be nominated by the British Bankers’ Association as the information vendor for the purpose of displaying London interbank offered rates for U.S. dollar deposits); (ii) if such rate cannot be identified on the related Determination Date, the Debenture Trustee will request the principal London offices of four leading banks in the London interbank market to provide such banks’ offered quotations (expressed as percentages per annum) to prime banks in the London interbank market for U.S. dollar deposits having a three-month maturity as of 11:00 a.m. (London time) on such Determination Date.  If at least two quotations are provided, 3-Month LIBOR will be the arithmetic mean of such quotations; (iii) if fewer than two such quotations are provided as requested in clause (ii) above, the Debenture Trustee will request four major New York City banks to provide such banks’ offered quotations (expressed as percentages per annum) to leading European banks for loans in U.S. dollars as of 11:00 a.m. (London time) on such Determination Date.  If at least two such quotations are provided, 3-Month LIBOR will be the arithmetic mean of such quotations; and (iv) if fewer than two such quotations are provided as requested in clause (iii) above, 3-Month LIBOR will be a 3-Month LIBOR determined with respect to the Distribution Period immediately preceding such current Distribution Period.  If the rate for U.S. dollar deposits having a three-month maturity that initially appears on Telerate Page 3750 as of 11:00 a.m. (London time) on the related Determination Date is superseded on the Telerate Page 3750 by a corrected rate by 12:00 noon (London time) on such Determination Date, then the corrected rate as so substituted on the applicable page will be the applicable 3-Month LIBOR for such Determination Date.

The Distribution Rate for any Distribution Period will at no time be higher than the maximum rate then permitted by New York law as the same may be modified by United States law.

All percentages resulting from any calculations on the Common Securities will be rounded, if necessary, to the nearest one hundred-thousandth of a percentage point, with five one-millionths of a percentage point rounded upward (e.g., 9.876545% (or ..09876545) being rounded to 9.87655% (or .0987655), and all dollar amounts used in or resulting from such calculation will be rounded to the nearest cent (with one-half cent being rounded upward)).

Except as otherwise described below, Distributions on the Common Securities will be cumulative, will accrue from the date of original issuance and will be payable quarterly in arrears on March 15, June 15, September 15 and December 15 of each year or if any such day is not a Business Day, then the next succeeding Business Day (each such day, a “Distribution Payment Date”) (it being understood that interest accrues for any such non-Business Day during the applicable Distribution Period, beginning on or after March 15, 2012), commencing on the Distribution Payment Date in March 2007. The Debenture Issuer has the right under the Indenture to defer payments of interest on the Debentures, so long as no Acceleration Event of Default has occurred and is continuing, by extending the interest payment period for up to 20 consecutive quarterly periods (each an “Extension Period”) at any time and from time to time on the Debentures, subject to the conditions described below, during which Extension Period no interest shall be due and payable.  During any Extension Period, interest will continue to accrue on the Debentures, and interest on such accrued interest will accrue at an annual rate equal to the Distribution Rate in effect for each such Extension Period, compounded quarterly from the date such interest would have been payable were it not for the Extension Period, to the extent permitted by law (such interest referred to herein as “Additional Interest”). No Extension Period may end on a date other than a Distribution Payment Date.  At the end of any such Extension Period, the Debenture Issuer shall pay all interest then accrued and unpaid on the Debentures (together with Additional Interest thereon); provided, however, that no Extension Period may extend beyond the Maturity Date.  Prior to the termination of any Extension Period, the Debenture Issuer may further extend such period, provided that such period together with all such previous and further consecutive extensions thereof shall not exceed 20 consecutive quarterly periods, or extend beyond the Maturity Date. Upon the termination of any Extension Period and upon the payment of all accrued and unpaid interest and Additional Interest, the Debenture Issuer may commence a new Extension Period, subject to the foregoing requirements. No interest or Additional Interest shall be due and payable during an Extension Period, except at the end thereof, but each installment of interest that would otherwise have been due and payable during such Extension Period shall bear Additional Interest.  During any Extension Period, Distributions on the Common Securities shall be deferred for a period equal to the Extension Period.  If Distributions are deferred, the Distributions due shall be paid on the date that the related Extension Period terminates, to Holders of the Securities as they appear on the books and records of the Trust on the record date immediately preceding such date. Distributions on the Securities must be paid on the dates payable (after giving effect to any Extension Period) to the extent that the Trust has funds available for the payment of such distributions in the Property Account of the Trust. The Trust’s funds available for Distribution to the Holders of the Securities will be limited to payments received from the Debenture Issuer.

The Common Securities shall be redeemable as provided in the Declaration.

ASSIGNMENT

FOR VALUE RECEIVED, the undersigned assigns and transfers this Common Security Certificate to:

(Sign exactly as your name appears on the other side of this Common Security Certificate)

Signature Guarantee(2)

(2)           Signature must be guaranteed by an “eligible guarantor institution” that is a bank, stockbroker, savings and loan association or credit union, meeting the requirements of the Security registrar, which requirements include membership or participation in the Securities Transfer Agents Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Security registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.